Details:

Creators:
Deng, Zhi-Qiang
Corporate Creators:
Louisiana State University. Department of Civil and Environmental Engineering
Corporate Contributors:
United States. Federal Highway Administration
Subject/TRT Terms:
[+]
Drainage Structures Elevated Highways Runoff Water--Pollution--Research--Louisiana Water Pollution
Publication/ Report Number:
FHWA/LA.08/466
Resource Type:
Tech Report
Geographical Coverage:
Louisiana
Edition:
Final report; Dec. 2007-May 2009.
Corporate Publisher:
Louisiana Transportation Research Center
Abstract:
The United States EPA (Environmental Protection Agency) MS4 (Municipal Separate Storm Water Sewer System) Program regulations

require municipalities and government agencies including the Louisiana Department of Transportation and Development (LADOTD) to

develop and implement stormwater best management practices (BMPs) for linear transportation systems to reduce the discharge of

various pollutants, thereby protecting water quality. An efficient and cost-effective stormwater BMP is urgently needed for elevated

linear transportation projects to comply with MS4 regulations. This report documents the development of a first flush-based stormwater

treatment device, the first flush reactor, for use on elevated linear transportation projects/roadways for complying with MS4 regulations.

A series of stormwater samples were collected from the I-10 elevated roadway section over City Park Lake in urban Baton Rouge.

Stormwater treatment experiments were conducted using three laboratory columns filled with different combinations of filter medium

layers. In terms of contaminant removal efficiency, the optimum filter medium combination was found to be (a) a mixture of Smart

Sponge and Hydra CX2 in the top layer, (b) zerolite in the next layer, (c) sand, (d) sawdust, and (e) gravel in the bottom layer. Results of

the laboratory experiments indicate that the first flush reactor with the optimized filter medium layers is able to remove over 85% of total

suspended solids (TSS), 90% of total phosphorus, 99% of NO2-N and NO3-N, and 70% - 90% of fecal coliform bacteria. Tested heavy

metals include Al, As, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Na, Ni, P, Pb, Si, and Zn. In general, removal rates of heavy metals through the

recommended filter media are higher than 80%. The removal rates of three toxic heavy metals including cadmium (Cd), copper (Cu), and

lead (Pb) are higher than 90%. Hydrocarbon levels in the stormwater samples were too low to be detected. Some unsolved problems in

the current design of the first flush reactor include the low removal rate (15%-58%) of TKN (Total Kjeldahl Nitrogen) and the slight

release (up to 20%) of toxic metal zinc (Zn) from the reactor. The problems may be resolved by conducting more column tests and

possibly replacing the Hydra CX2 with other types of fiber mulch. Experimental results presented in this report may be used for further

study of filter medium selection and for optimization of the first flush reactor.

Guidelines for design, field construction, operation, and maintenance of the first flush reactor are provided in this report to help

environmental engineers and stormwater managers design and operate the first flush reactor properly and achieve the stormwater

pollutant removal efficiency required in the MS4 program.


Format:
PDF
Funding:
LA 736-99-1516 ; LTRC 08-3TIRE
LA 736-99-1516 ; LTRC 08-3TIRE Less -
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:8132f5138768ad9dd40f98b524c111aadd3e93373d4b5c231015ceb8a8a52050
Download URL:
https://rosap.ntl.bts.gov/view/dot/17815/dot_17815_DS1.pdf
File Type:

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